Some older versions can be found below. The few executable links tried did work. Can't say if they will all work.
http://web.archive.org/web/200905272052 ... d/?C=M;O=DAlternately can also try the show all files way.
http://web.archive.org/web/*/http://ftp ... winboard/*I think I remember correctly from reading on this forum that there was some kind of problem with a component of the older Winboard packages, timeseal or something, not being open source, so GNU decided to no longer host the older Winboard versions, so archive site is best option for those. I'm open to being corrected.